The aim of this proposed training program is to prepare postdoctoral fellows (physicians and behavioral scientists) for research careers in the cross-disciplinary field of HIV and other infections associated with substance abuse. Young investigators are urgently needed to develop new approaches to better understand, prevent, and treat the range of infectious consequences encountered in the substance using population. In order for any intervention on behalf of this community to be successful, a cross-disciplinary approach utilizing appropriate behavioral and medical models must be used. Therefore, it is proposed that this program offer training in five specific areas: infectious diseases, healthcare delivery, 0B-GYN, pediatrics, and behavioral medicine. Trainees will have the opportunity to train specifically in one or more areas. Training will consist of a two-year block in which fellows will follow a program unique to their research interests under the guidance of a primary faculty mentor. The combined resources of the Miriam Hospital Immunology Center, Brown University School of Medicine and affiliated hospitals, centers, and specialized clinics such as the Adult Correctional Institute (ACI) and community drug treatment centers will offer a rich, hands-on training environment for each fellow. A common academic curriculum structured in a cross-disciplinary manner as well as an optional MPH degree will also be offered with this program. Fellows will attend conferences in their specialty as appropriate. Each fellow will conduct a research project and be required to write and submit a funding proposal (R03) at the conclusion of the program. This training experience will allow each fellow to become familiar with a specific area of research, provide that person with basic research techniques, and give the trainee insight into productive approaches to scientific questions. Support is requested for three postdoctoral trainees per year.